Charging unit



FIG. 1 is a perspective view of the charging unit;

FIG. 2 is a front view of the charging unit;

FIG. 3 is a back view of the charging unit;

FIG. 4 is a left side view of the charging unit;

FIG. 5 is a right side view of the charging unit;

FIG. 6 is a top view of the charging unit; and,

FIG. 7 is a bottom view of the charging unit.

The broken lines in the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a charging unit, as shown and described. 